1. Field of the Invention
This invention relates to a mooring cleat and in particular though not solely to a retractable mooring cleat which is automatically operable to retract in to the deck or some other surface of a boat while at the same time automatically releasing an attached mooring line.
2. Background Art
Mooring cleats (also known as bollards in some countries/situations) are widely used in the marine industry to tie lines (such as ropes or cables) to. Cleats usually have two, but may have more, projecting ends and are fixed to a surface (such as the deck) of a marine vessel. Retractable mooring cleats were developed to provide a “flush” or smooth deck when the cleat is not in use. This is both visually appealing and safer for boat crew. Most existing retractable mooring cleats are manually retractable into the deck or other surface of a boat.
An example of a manually retractable mooring cleat is disclosed in U.S. Pat. No. 5,004,388A wherein a spring biased cleat is telescopically moveable vertically within a hollow housing mounted in the deck of a boat. The cleat is locked in position within the housing by a locking mechanism which is released by a user manually depressing the cleat which then moves to its extended position under the force provided by the spring.
An automatically retractable cleat is disclosed in WO 03/086854. This document discloses various embodiments of retractable cleat including cleats which retract by rotating about a horizontal axis just below the deck surface and automatically vertically retractable cleats. However, before any of the disclosed cleats may be retracted, any attached mooring line or rope must first be manually removed.
U.S. Pat. No. 4,531,470A discloses a mooring line coupler which is not retractable but which is operable to automatically release an attached rope having a preformed loop at its end through which a vertically projecting part of the cleat passes to lock the rope in position. A solenoid pin normally holds the projecting part in the vertical plane. The pin is retractable to allow the projection to swing (under a spring bias) away from its vertical position thereby releasing the rope.
None of the above documents disclose a retractable cleat that, during retraction, is capable of extricating itself from an attached mooring line. It would be an advantage to provide an automatically retractable cleat which also automatically released an attached mooring line as it was retracted or during the retraction process and wherein standard mooring lines could be used.
Accordingly, it is an object of the present invention to provide a retractable cleat which will go at least some way towards meeting the above desiderata or which will at least provide the public with a useful choice.
In a first aspect, the invention consists in a retractable cleat comprising:
a frame having an upper surface,
a first member extendable from said upper surface along a first path,
a second member extendable from said upper surface along a second path, divergent from the first path, and
an actuation mechanism mounted on said frame operable to cause the first and second members to move along the first and second paths respectively to either protrude from the said upper surface or to retract below, or substantially flush with, said upper surface.
Preferably, the movement between the upper surface and the first or second member respectively is a purely sliding action.
Preferably, the movement between the upper surface and the first or second member respectively is a sliding and/or twisting action.
Preferably, the first and second paths are enclosed entirely within the three dimensional volume defined by the first and second members respectively when at their fully extended positions.
Preferably, the cross-section of the first and/or second members are constant along their length, at least along the portion which is able to protrude from the frame.
Alternatively, the first and/or second members are tapered towards their ends which extend from the frame.
Preferably, the first and second members have a circular cross-section.
Alternatively, the first and second members have a substantially square cross-section.
Preferably, the first and second members are substantially straight.
Alternatively, the first and second members are curved.
Preferably, the first and second members are curved in fixed radius arcs.
Preferably, the first and second members are helical and moved along their respective paths by a screwing action.
Preferably, the force applied by the first and second members is greater at the start of retraction and reduces towards the end of retraction.
Preferably, a base plate forms said frame.
Preferably a housing forms said frame.
Preferably, each of the first and second members are each supported within the housing by at least one fixed bushing through which the first or second member respectively is able to slide.
Preferably, the first and second members are each supported within the housing by two fixed bushings that are formed from a compressible material.
Preferably, the bushing or bushings have an opening that matches the cross-sectional shape of the first and second members.
Preferably, the first and second members have lower ends that remain below the upper surface of the housing and upper ends that are extendable above housing's upper surface wherein the first and second members have a stop projecting outward at or near their lower ends and lower bushings on the respective first and second members include a depression shaped to receive the stop when the member is in its fully extended position.
Preferably, the first and second members have lower ends that remain below the upper surface of the housing and upper ends that are extendable above the housing's upper surface, wherein a first driving member is pivotally connected at or near the lower end of the first member and a second driving member is pivotally connected at or near the lower end of the second member and the actuation mechanism includes a source of motive energy connected to drive the first and second driving members to thereby cause the first and second members to move along their respective paths.
Preferably, the first and second driving members each include a rack formation and the source of motive energy is connected to rotate drive wheels, one of which engages with the rack formation on the first driving member and another of which engages with the second driving member.
Preferably, the source of motive energy comprises an electric motor that rotates a worm gear coupled to drive a worm gear wheel that is coupled to rotate the drive wheels.
Preferably, actuating means are provided to manually disengage the source of motive energy from the drive wheels.
Preferably, the actuation mechanism comprises a plurality of interconnected gear wheels between a central drive wheel, that is driven directly by the worm gear wheel, and the rack formations and the actuating means comprise a lever adapted to disengage the central drive wheel from its connection to the worm gear wheel.
Preferably, the central drive wheel and the worm gear wheel are mounted on the same shaft with the worm gear wheel slidable and rotatable on the shaft and the central drive wheel fixed to the shaft so that it is movable axially with the shaft and rotatable thereon, wherein the central drive wheel and the worm gear wheel are engaged together by a dog clutch formed by features on their adjacent side surfaces when the shaft is in a first position and disengaged when the shaft is moved axially to a second position that moves the central drive gear away from the worm gear wheel.
Preferably, biasing means are provided to urge the first and second members away from their fully retracted positions.
Preferably, the biasing means comprise a spring that stores mechanical energy as the first and second members are retracted and is connected to provide a resultant torque to one of the first or second members in a direction to cause extension of the first and second members.
In a second aspect, the invention consists in a retractable cleat comprising:
a housing having an upper surface,
at least one first member, the or each first member extendable from the housing's upper surface along a respective first path,
at least one second member, the or each second member extendable from an associated first member along a respective second path, and
an actuation mechanism operable to cause the or each first member to move along their respective first paths to either protrude from the upper surface or to retract below, or substantially flush with the upper surface and to cause the or each second member to move along their respective second paths to either protrude from or to retract within their associated first member.
Preferably, extension and retraction of a second member occurs while its associated first member is fully extended.
Preferably, each first path is substantially straight and perpendicular to the housing's upper surface.
Preferably, each second path is substantially straight and perpendicular to the first path of its associated first member.
Preferably, the retractable cleat includes one first member and at least two associated second members.
Preferably, the retractable cleat includes two spaced apart first members, each including a single second member extendable therefrom wherein the respective second paths extend in opposite directions.
Preferably, the or each first member comprises a post having an oblong cross-sectional shape viewed in the direction of the first path.
Preferably, a base plate forms the outer surface of the housing.
In a third aspect, the invention consists in a marine vessel including at least one retractable cleat according to the first or second aspects, mounted in a cavity formed in or beneath a surface in the marine vessel.
Preferably, a plurality of retractable cleats are provided within respective cavities beneath or in a surface or surfaces of the marine vessel and the actuation mechanism of each retractable cleat is operable in unison.
To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.